1. Field of the Invention
The present invention relates to a position detecting apparatus and a position detecting method each of which uses a magneto-resistive (MR) element, an optical sensor, and the like, and further an optical apparatus that uses these.
2. Description of Related Art
Conventionally, a position detecting apparatus that uses a magnetoresistive element (hereinafter, this is called an MR element) detects a position by selecting a phase having a signal component with excellent linearity among sinusoidal analog signal components outputted from the MR element with a plurality of phases, and by performing the calculation of interpolating the signal component.
Here, since a phase with a signal component excellent in linearity suitable for interpolation varies according to a position of a measuring object, it is switched at any time according to a position change of the measuring object.
Nevertheless, in the conventional position detecting apparatus described above, position detection result at the time when a phase used for the interpolation is switched to another may become discontinuous when gains and offsets are not accurately adjusted to sinusoidal position detecting signals with a plurality of phases, when gains and offsets of the position detecting signals vary by a drift, a change of environmental temperature, and the like. Owing to this, the accuracy of the position detection may decrease in the vicinity of a position of the object where the change of the phases used for the interpolation occurs.